Isotope separators



6, 1958 c. G. BACON ISOTOPE SEPARATORS 2 Sheets-Sheet 1 Filed Jan. 9, 1945 K e "(V/JP 2 n m 5 g we PB m I J Am. 5 5 n 5/ m T J m m w m f'l' nfi.

I N V EN TOR. Conrad G. Bacon A 26, 1958 c. G. BACON 2,849,616

ISOTOPE SEPARATORS Filed Jan. 9, 1945 2 Sheets-Sheet 2 INVENTOR. Conrad G. Baco?2 ISUTOPE SEPARATORS Conrad G. Bacon, @ak Ridge, Tenm, assignor, by mesne This invention is concerned generally with isotope separating apparatus and is particularly concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus.

The particular isotope separating apparatus or equipment in which my invention is employed is of the type disclosed in detail in the prior application of Ernest 0. Lawrence, Serial No. 557,784, filed October 9, 1944, now U. S. Patent No. 2,709,222, issued May 24, 1955.

The isotope separating apparatus is disposed within a tank which is evacuated to a relatively high degree of vacuum, and the apparatus includes an ion source or generator of the type wherein an electric arc is struck for purposes of producing ionization of a material, the isotopes of which it is desired to separate. It is desirable to provide a window in the tank so that operators can observe the process within the tank and particularly so that the operators can observe the are or arcs constituting the ion source.

An object of my invention is to provide a window in apparatus of the type described above having associated therewith a closure member for the window, or a shutter which is magnetically operated between closed and open positions by utilizing the magnetic field which is a part of the isotope separating apparatus. The aim of this object is to eliminate the use of a sliding seal in the side wall of the tank which would be necessary if the shutter were to be mechanically actuated from the exterior of the tank.

Another object of the invention is to provide a magnetically operated shutter as referred to above which is operated between open and closed positions by opening and closing an electric circuit and which embodies spring means arranged to insure against the shutter sticking in one position.

Another object of the invention is to provide a shutter as described in the foregoing objects embodying an electrical winding energizable manually and de-energizable in response to an automatic interval timer so that the operator need only perform a single manual act with the shutter returning to its original position after a given interval of time.

Further objects of my invention and numerous of its advantages will be apparent from the following detailed description and annexed drawing wherein Fig. l is a cross sectional view of isotope separating apparatus of the type wherein my invention may be embodied.

' Fig. 2 is a diagrammatic end view of the apparatus of Fig. 1 showing the magnetic field producing means in cross section.

Fig. 3 is a diagram of the electric circuit which controls the magnetic shutter.

Fig. 4 is a detail sectional View of the magnetic shutter taken along the line AA of Figs. 1 and 5.

Fig. 5 is a detail sectional view of the magnetic shutter taken along the line B--lB of Fig. l or Fig. 4.

2,849,6 l6, Patented Aug. 26, 1958 Referring to Fig. l of the drawings wherein the isotope separating apparatus is diagrammatically shown, the apparatus comprises a tank 10 which is rectangular in cross section and one side of which is closed and sealed by a relatively massive face plate 11 which is attached to the tank by screw clamps, one of which may be seen at 12, the face plate 11 and the tank It) having bearing surfaces which mutually engage each other when the face plate is in position so as to provide vacuum tight sealing engagement between the tank'and face plate.

Disposed on opposite sides of the tank 10 are laminated iron cores or pole pieces 13 as may be seen in Fig. 2 and surrounding these pole pieces are electrical windings 14 as may be seen on Figs. 1 and 2. Windings 14 are within housings 15 as shown disposed on opposite sides of the tank 10. The windings 14 are electrically energized so as to cause a relatively intense magnetic field to be produced which is in a direction transverse to the tank it that is, in a horizontal direction looking at Fig. 2 and in a direction perpendicular to the paper looking at Fig. l.

The tank 10 has an outlet 18 through which air and moisture from within the tank are evaculated by means of a diffusion pump or pumps 19 connected to the outlet by pipe 20, the diffusion pump or pumps being backed by, that is, connected to a mechanical pump or pumps 21 by a pipe as shown. The mechanical pumps may be Kinney pumps for example.

Within the tank It} is an ion source unit or generator designated generally at 25 consisting of two identical ion generating sources. The ions generated by the source unit are accelerated upwardly from the units, that is, to the left into a liner 26 in the form of an arcuate conduit within which the ions, which are positive ions are caused to move in arcs of a circle under the influence of the magnetic field, the radii of the arcs being dependent upon the mass-charge properties of the ions. The ions which travel within the liner 26 are received in a receiver in the opposite end of the liner and not shown on Fig. 1. The application identified above may be referred to for more details of the isotope separating apparatus.

The ion source units 25 and the liner 26 are supported from face plate 11 by frame structure 27 and brace mem ber 28. Each of the ion source units comprises a casting as indicated at 30 comprising a container for a material to be ionized which is vaporized within the casting by heatingmeans not shown. The vaporized material passes out through the top of the container 30 through a slit indicated at 31 and means are provided for striking an electric are substantially within the slit 31 in the vaporized material. The are producing means comprises a cathode and an anode whereby a stream of electrons is projected longitudinally in the slit 31 as to ionize the vapor passing through the slit. The positive ions are accelerated towards the liner 26 by means of an accelerating electrode 32 which is maintained at a high negative potential into a throat 33 which is also maintained at a relatively high negative potential and thence into liner 26.

The magnetic shutter of my invention is designated at 35, being associated with a circular port or window 36 so disposed in the tank 10 that when the shutter is moved away from the window, one may observe he arc in the ion source units, there being an opening 37' in the liner 26 so that the view of the operator is not obstructed.

Referring now to Figs. 4 and 5, it will be seen that the shutter is mounted to swing about an axis or spindle which is not vertical, but which is at an angle of substantially 20 degrees from the vertical. The shutter 35 itself comprises a plate 37 and its configuration may best be seen on Fig. 5. The plate 37 has an angular bracket portion 38 the end of which is bent around a spindle 39so as to form a hinge. The ends of the spindle 39 are journalled in upstanding portions of a U bracket member 40 which is attached to the end wall of the tank 10 as shown on Fig. 5. The bracket portion 38 is spaced from the upstanding portions of U bracket 40 by washers 41 as shown. In operation, the shutter 35 swings inwardly into the tank when moving away from the window and this would be out of the paper so to speak, when looking at Fig. 4. The plate 37 has edge portions bent as shown at 44 and 45 so that these portions may serve as stops by engaging the end of tank 18 to limit the travel of the shutter towards the window. Numeral 46 designates a right angle member attached to the bracket 48 and secured to the right angle member 46 is a resilient spring arm or finger 47 which protrudes lnwardly into the tank as may be seen on Fig. 1 and against which the shutter swings when it is moved in a direction to open the window.

The shutter is actuated by means of an electrical coil winding 48 of circular conformation as may be seen on Figs. 4 and which is Wound on a cylinder 49, the cylinder 49 being disposed between plate 37 and another plate 50 as seen on Fig. 5, the parts being held in assembled relationship by means of soldering or the like.

When the shutter 35 swings away from the Window, that is, in clockwise direction looking at Fig. 5, it engages the spring arm 47 and springs it slightly to the right, the shutter being held in that position as long as the winding 48 is energized; when the winding is deenergized, it swings back in the other direction, being given a start by the resiliency of the spring arm 47 and the shutter then swinging back into position covering the window under the influence of gravity, since the shutter is mounted on a spindle which is at an angle to the vertical as described. That is, when the shutter swings in opening direction, it must necessarily move upwardly to some extent.

The primary purpose of the shutter of course is to protect the glass of the window from becoming fouled up with condensate or other material which may result from the process going on within the tank 10.

Summarizing the operation of the shutter, it is that when the winding 48 is energized electrically from outside of the tank (as will be described) the winding attempts to orient itself to a position wherein the winding is at right angles to the magnetic field; that is, the shutter 35 will swing about its hinge clockwise looking at Fig. 5 and towards the interior of the tank looking at Fig. l. The shutter swings against the spring arm 47 and remains in that position as long as the winding 48 is energized and when the winding is de-energized, the spring arm 47 gives the shutter a start in the other direction, and it then swings back under the influence of gravity into its position as shown on Figs. 1 and 5.

My invention provides means whereby the operator may manually energize the winding 48 from outside of the tank by means of depressing a push button, and the shutter will then remain in open position for a predetermined period of time while the operator is observing conditions within the tank, and the shutter will then automatically resume its original position. The circuit for operating the shutter is shown in Fig. 3. It comprises an interval timer 51 which may be a commercial interval timer known as the Sangamo Interval Timer. The interval timer is originally energized or started by a circuit controlled by push button 52, and when the timer is thus energized and started, it closes a circuit energizing the primary of a transformer 53 and also energizing the winding of a relay 54 which closes a circuit shunting the push button switch 52 so that the transformer 53 and relay 54 remain energized until the timer goes through its cycle which requires a predetermined interval of time, after which the timer interrupts the original circuit which was closed by depressing the push button 52. The transformer 53 has a primary winding 55 and a secondary winding 56 which supplies energy to a rectifier 57 of conventional type which supplies in turn, direct current 4 to the winding 48. The output of rectifier 57 is connected to winding 48 by wire 58 which passes through a spark plug 61 sealed in the side of tank 10, and to ground by wire 59. The other terminal of winding 48 is grounded by wire 60 connecting to the tank 10. There is enough slack in the connections to winding 48 to not interfere with its movement (see Fig. 5). When the push button 52 is depresed, the winding 48 is energized and the shutter 35 swings away from the window 36, and remains in the open position while the timer 51 goes through its cycle, that is, for a predetermined interval after which the timer automatically de-energizes the winding 48 and the shutter returns to its original position.

From the foregoing it is to be seen that my invention provides an avantageous and convenient means for protecting the window in the tank against becoming fouled up and furthermore it eliminates the need of a sliding seal in connection with the shutter and consequent possibilities of leakage through the seal. The automatic timing circuit provides for automatically returning the shutter to closed position over the window so that the possibility of the operator forgetting the shutter and leaving it in open position is obviated.

The disclosure herein represents a preferred form of my invention, and is to be interpreted in an illustrative rather than a limiting sense, the scope of the invention being delineated in accordance with the claims appended hereto.

I claim:

1. In apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a relatively intense magnetic field within said chamber, means forming a window in said chamber, means forming a closure operable between a first and second position for covering said window, operating means for said closure including an electrical winding disposed in said magnetic field, and said electrical winding means being operable when energized to move said closure to the second of its positions.

2. In apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a relatively intense magnetic field within said chamber, means forming a window in said chamber, means forming a closure operable between a first and second position for covering said window, operating means for said closure including an electrical winding disposed in said magnetic field, said electrical winding means being operable when energized to move said closure to the second of its positions, and resilient means arranged so as to be operable to urge said closure away from said second position.

3. in apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a relatively intense magnetic field within said chamber, means forming a window in said chamber, means forming a closure operable between a first and second position for covering said Window, operating means for said closure including an electrical winding disposed in said magnetic field, said electrical winding means being operable when energized to move said closure to the second of its positions, control mechanism including means for manually energizing said electrical winding means and automa ically de-energizing said winding means after a predetermined interval so that the closure remains in the sec- 0nd of its positions during the interval.

4. in apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a reiatively intense magnetic field within said. chamber, means forming a window in said chamber, moans forming a closure operable between a first and second position for covering said window, operating means for said closure including an electrical winding disposed in said magnetic field, said electrica winding means being operable when energized to move said closure to the second of its positions, and resilient means arranged to be operable to urge said closure away from said second position, and control mechanism including means for manually energizing said electrical winding means and automatically de-energizing said electrical winding means after a predetermined interval so that the closure remains in the second of its positions during the interval.

5. In an apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a relatively intense magnetic field Within said chamber, means within said chamber comprising a device mounted to swing under the influence of said field and including an electrical winding and being so mounted as to swing in one direction under the influence of gravity, the axis about which the device swings being inclined at a relatively small angle to the vertical, and means for energizing the electrical winding.

6. In an apparatus of the character described, in combination, means forming a vacuum chamber, means for evacuating said chamber, means for producing a relative intense magnetic field within said chamber, means Within said chamber comprising a device mounted to swing under the influence of said field and including an electrical winding and being so mounted as to swing in one direction under the influence of gravity, the axis about which the device swings being inclined at a relaitvely small angle to the vertical, means for energizing the electrical winding and spring means arranged to urge said device in the direction in which it moves under the influence of gravity.

7. In an apparatus of the character described, in combination, means forming a vacuum chamber having a window, means for evacuating said chamber, means for producing a relatively intense magnetic field within said chamber, means within said chamber comprising a closure member for said window mounted to swing under the influence of said field and including an electrical winding and being so mounted as to swing in one direction under the influence of gravity, the axis about which the member swings being inclined at a relatively small angle to the vertical, and control mechanism including means for manually energizing said winding and for automatically de-energizing said winding after a predetermined interval.

8. In an apparatus of the character described, in combination, means forming a vacuum chamber having a window, means for evacuating said chamber, means for producing a relatively intense magnetic field within said chamber, means within said chamber comprising a closure member for said window mounted to swing under the influence of said field and including an electrical winding and being so mounted as to swing in one direction under the influence of gravity, the axis about which the mem ber swings being inclined at a relatively small angle to the vertical, and spring means arranged to urge said member in the direction in which it moves under the influence of gravity, and control mechanism including means for manually energizing said winding and for automatically de-energizing said winding after a predetermined interval.

9. In apparatus of the character described, in combination, means forming a chamber having an ion source therein, means for producing a magnetic field within the chamber, means forming a viewing window positioned in said chamber to permit observation of the operation of said ion source, a closure member for said window operable to cover and uncover said window, electromagnetic means in the magnetic field for operating the closure member, and means for energizing and de-energizing the electromagnetic means.

References Cited in the file of this patent UNITED STATES PATENTS 475,338 Oliver May 24-, 1892 599,800 Scribner z Mar. 1, 1898 2,253,252 Smith Aug. 19, 1941 2,370,673 Langmuir Mar. 6, 1945 2,377,133 De Costa May 29, 1945 

